Heat sealing apparatus



, June 1969 L. H. GIRARD 3,449,195

HEAT SEALING APPARATUS Filed April 12. 1966 7 Sheet ZFZL F61 y s IN\/I;1\ 1 UK. LAURENT H. GIRARD gm W m ATTORNEYS June 10, 1969 H. GIRARD 3,449,195

\ HEAT SEALING APPARATUS Filed April 12. 1966 Sheet 3 of 4 v. INVENTOR LAURENT H GIRARD ATTORNEYS June 10, 1969 L. H. .GIRARD 3,449,195

HEAT SEALING APPARATUS Filed April 12, 1966 Sheet 3 of 4 FIG. 5

1N\ 'EN'I'OA. LAURENT H. GI RARD 5Q Ma ma?! ATTORNEYS June 1969 L. H. GIRARD 3,449,195

HEAT SEALI NG APPARATUS Filed April 12. 1966 Sheet 4 of 4 w I 8| 73 I 3 n I 60 LAURENT H. GIRARD 1%}? M i M;

ATTORNE YS United States Patent US. Cl. 156-443 9 Claims This is a continuation-in-part of my co-pending application, Ser. No. 433,341 filed Feb. 17, 1965.

This invention relates to heat sealing apparatus and more particularly it relates to apparatus for holding por tions of sheet material in overlapping relationship and heat sealing them together. It also relates to apparatus for holding a ring in position for insertion of a length of sheet material therein and folding the inserted sheet material back against itself and heat sealing overlapping portions together.

The pile fabric to which the invention has particular applicability is generally described in US. Patent No. 3,009,325. Basically, the pile fabric sheet material consists of a base of sheet material which has a surface defined :by hooking elements secured thereto in positions extending generally vertically from one surface of the base sheet material to which they are secured. The hooking elements are formed from a flexible resilient material into either hooks or loops of the type characterized by the property that pressing a surface defined by the hooks in face-to-face relation with a surface defined by the loops will result in a large number of hooks engaging a large number of loops to secure the members in face-to-face relation.

In my co-pending application referred to above, a method is described for joining lengths of this pile fabric lengthwise to form a more extended length of one type of hooking element or a composite structure of the two types of hooking elements. The method described involves skiving the hooking elements down to the surface of the base material usually along a marginal end portion of a length of pile fabric so as to present a rather fiat smooth marginal end portiton which is substantially free from the vertically extending hooking elements. A marginal end portion is then overlapped with a second length of sheet material, and adhesive is placed between the two flat surfaces and they are joined together by a heat sealing operation. Also described in my co-pending application is a composite length of hook and pile tape joined together with a ring at one end to form a strap.

This invention relates to apparatus for overlapping portions of sheet material and heat sealing them together. The portions of the sheet material can be either marginal end portions of separate lengths of either hook or loops or it can be an end portion of a length of sheet material which is inserted into a ring and folded back against itself in overlapping relationship and heat sealed together. Broadly stated, the apparatus comprises a pair of heat sealing elements mounted for reciprocal movement to and from a heat sealing station and means for reciprocating the heat sealing elements to and from the heat sealing station. Sheet material guide means are provided for receiving portions of the sheet material and positioning them in overlapping relationship at the heat sealing station and means are provided for moving the guide means away from the heat sealing station before moving the heat sealing elements in contact with the sheet material at the heat sealing station.

The invention also provides apparatus which includes means for holding a ring adjacent the heat sealing station in position for an end of the sheet material to be inserted through the ring and other means for folding 3,449,195 Patented June 10, 1969 an end portion of the sheet material around a portion of the ring and back against itself in overlapping relationship at the heat sealing station.

Preferred embodiments of the invention are described hereinbelow with reference to the drawing wherein:

FIG. 1 is a fragmentary side elevation of one embodiment of the invention;

FIG. 2 is a fragmentary front elevation of the apparatus shown in FIG. 1;

FIG. 3 is an enlarged fragmentary elevation of the heat sealing station of the first embodiment of the apparatus;

FIG. 4 is a fragmentary plan view of a second embodiment of the invention in a first position;

FIG. 5 is an enlarged fragmentary front elevation of the second embodiment in a second position;

FIG. 6 is a fragmentary front elevation of the second embodiment of the invention in a third position; and

FIG. 7 is a fragmentary front elevation of the apparatus of the first embodiment in its fourth sealing position.

Referring initially to FIGS. 1-3, a first embodiment of the invention is shown. The apparatus is comprised of a vertical column 10 which supports a heat sealing device 11 (the control box of which is not shown). Extending downwardly from the control box of the heat sealing device 11 is a top cylinder 12 which has a heating element 13 connected to the cylinder rod. Underlying the top cylinder 12 is a bottom cylinder 14 which also has a heating element 15 connected to its cylinder rod. The heating units 13 and 15 have a polytetrafluoroethylene covering 16 and 17 which is secured around the heating elements by means of clips 18 and 19; this covering prevents the heating elements from becoming attached to the material during sealing. This heating device 11 is of standard construction and one which is preferred in this apparatus is a device marketed under the trademark Electro-Sealer by Electro-Seal Corporation, Maywood, New Jersey. This device contains controls over the temperature of the heating element and is designed to bring the top heating element 13 and the bottom heating element 15 together at a heat sealing station 20 by actuating the reciprocating air cylinders 12 and 14.

Attached to the column 10 by means of a clamp 21 are table supporting plates 22 and 23 which extend laterally outwardly from the column in a substantially horizontal position and are in parallel spaced relationship to provide a space 24 therebetween to permit the bottom heat sealing element 15 to pass therebetween. A table 25 is supported on the table supporting plates 22 and 23 and has an opening 26 therein which overlies the space 24 and substantially defines the heat sealing station 20. Positioned on the table 25 and extending laterally across the table on opposite sides of the heat sealing station 20 are respective pairs of parallel spaced guide plates 27, 27', 28 and 28' which define an elongated positioned channel 29, 29 therebetween. The plates are adjustable on the table and are fixed on the table by locating pins 30, 30', 31 and 31. The channels 29 and 29' are adjusted to receive tapes 32 and 33 therein to position their marginal end portions 34 and 35 at the heat seal station 20.

Attached to the table 25 on opposite sides of the heat seal station 20 and overlying the channels 29 and 29 are a pair of air cylinder 36 and 37 which are mounted on the table by means of L-shaped upstanding brackets 38 and 39. Extending downwardly from the cylinders 36 and 37 are cylinder rods 40 and 41 which have end portions 42 and 43 for contacting the tape and holding it in the channel.

Positioned at the heat seal station are a top guide plate 44 and a bottom guide plate 45. The top guide plate 44 has a laterally extending slot 46 provided therein into which marginal end portion 34 of the first length of tape 32 is positioned and bottom plate 45 has a laterally extending slot 47 for receiving the marginal end portion 45 of the second length of tape 33. When the marginal end portions 34 and 35 are positioned in the guide plates 44 and 45 they are in spaced overlapping relationship with each other. The guide plates 44 and 45 are connected to an L-shaped bracket 48 which extends from the heat sealing station toward the column and is adjustably mounted to a laterally extending plate 49 which has an upstanding contact plate 50 attached to it. The plate 49 is fixed to a cylinder rod 51 at one portion and the cylinder rod is connected to an air cylinder 52. Mounted on the air cylinder 52 is a microswitch 53 which has a trip plate 54 extending from the switch in position to be contacted by contact plate 50 when the guide elements 44 and 45 are retracted from the heat sealing station 20. The microswitch 53 is connected to the heat sealing device and when actuated it actuates the top and bottom heating elements 13 and 15 and brings them together at the heat sealing station as shown in FIG. 3.

In operation, a first length of tape 32 is positioned in guide channel 29 and its marginal end portion is inserted in slot 46 of guide plate 44. A second length of tape 33 is inserted in guide channel 29 and its marginal end portion 35 is inserted in slot 47 of the bottom guide plate 45. The air cylinders 36 and 37 are actuated and the tape held in position by pressing contact of the end portions 42 and 43 of the cylinder rods 40 and 41. Air cylinder 52 is then actuated causing plate 49 to be retracted and sliding the guide plates 44 and 45 away from the heat sealing station with the marginal end portions 34 and 35 sliding out of the slots in the guide plates in overlapping relationship at the heat sealing station. Upon full retraction of the plate 49, the contact plate 50 actuates the microswitch trip plate 54 and the heating elements 13 and 15 are brought together at the heat sealing station where they contact the overlapping marginal end portions 34 and 35 of the tape and by heat and pressure seal them together. An adhesive is usually used between the interface of the seam being formed and the adhesive is ordinarily positioned on either of the two marginal end portions prior to being inserted in the apparatus.

Referring now to FIGS. 4-7, a second embodiment of the invention is shown. The heat sealing device of the second embodiment is identical to that of the first embodiment and comprises a column 10' on which the heat sealing device is supported and holds top heating elements 13' and a bottom heating element 15' in position to be moved toward and away from a heat sealing station 60. The apparatus also includes a microswitch 53' and a microswitch trip plate 54'. A cylinder similar to the cylinder 52 of the first embodiment (not shown) is also provided and has a cylinder rod 51' connected to a plate 49' which has an upstanding contact plate member 50' extending in position to contact the microswitch trip plate 54 when the cylinder rod is in its retracted position.

Attached to the column 10' in the same manner as that described in the first embodiment are table support plates 22' and 23' which support a table in a horizontal position. A space 26' is provided in the table and the table support members 22 and 23' are spaced apart defining a space 24' therebetween. On one side of the heat seal station 60 there is provided a pair of parallel spaced guide plates 61 and 62 which define a channel 63 therebetween for positioning a length of tape 64 as shown in FIG. 4. Connected to the reciprocal plate 49' is an L-shaped adjustable bracket member 65 which has an inclined bot-- tom plate portion 66 positioned at the heat sealing station 60 in the extended position of the cylinder rod 51'. Also secured to the reciprocal plate 49' is a second smaller adjustable L-shaped bracket 67 which has a bottom laterally extending shoulder portion 68 that defines an abutting surface 69 for an end portion of the tape 64. On the opposite side of the heat sealing station to the guide channel 64 and supported on the table 25 is a device 70 for inserting an end portion of the tape 64 into an end ring. This device 70 consists of a base plate 71 which is mounted on the table 25' and extends over the opening 26 with an end portion 72 adjacent the heat seal station 60. Positioned on the end portion 72 is a raised shoulder portion 73 which is sized to receive an end ring 74, here a D-ring. Mounted on the base plate 71 is a first slide plate 75 which has one end portion 76 connected to a cylinder rod 77 of a cylinder 78. By actuating the air cylinder 78, slide plate 75 can be brought into abutting relationship with one portion of the D-ring 74 and hold it adjacent the heat seal station spaced from the raised shoulder 73 so that an end portion 74 can be inserted into the ring.

Once the end portion of the tape 64 is inserted in the ring 74, the end edge of the tape 79 is abutted against the shoulder 69 of the bottom portion 68 of the bracket 67. A second slide plate 80 which is fixed to first slide plate 75 and is moveable with the first slide plate 75 in a direction toward the heat sealing station 60 as shown in FIG. 5 has one end portion 81 connected to a cylinder rod 82 of an air cylinder 83 and upon extension of the cylinder rod 82 the opposite end portion 84 of the second slide plate is moved toward the heat sealing station causing a marginal end portion 85 of the tape to be folded over the D-ring 74 and back against itself at the heat sealing station.

The reciprocal plate 49 can then be withdrawn to its retracted position so that the guide bracket 65 is removed from the heat sealing station. In its fully retracted position, the upwardly extending contact portion 50' of the plate 49' contacts the microswitch trip plate 54 and the heat sealing elements 13 and 15 are brought into contact at the heat sealing station 60 and by pressure and heat seal, the marginal end portion 85 of the tape to that portion of the tape which it overlaps as shown in FIG. 7 thereby securing the D-ring to an end portion of a length of tape.

It is to be noted that an adhesive can be applied to the marginal end portion of the length of sheet material prior to insertion into the ring; folding of the marginal end portion overlaps the marginal end portion against a back surface of the sheet material which has no pile elements extending therefrom.

I claim:

1. Apparatus for overlapping portions of sheet material and heat sealing them together comprising:

(a) a pair of heat sealing elements mounted for reciprocal movement to and from a heat sealing station,

(b) means for reciprocating the heat sealing elements to and from the heat sealing station,

(0) sheet material guide means for receiving portions of sheet material and positioning them in overlapping relationship at the heat sealing station, and

(d) means for moving the guide means away from the heat sealing station before moving the heat sealing elements into contact with the sheet material at the heat sealing station.

2. Apparatus according to claim 1 wherein said guide means include a top guide plate having a slot for receiving a marginal end portion of a first length of sheet material and a bottom plate having a slot for receiving a marginal end portion of a second length of sheet material.

3. Apparatus according to claim 1 including switch means in position to be actuated by said guide means for automatically moving the heat sealing elements to and from the heat sealing station as the guide means are moved away from and toward the heat sealing station.

4. Apparatus according to.claim 1 including means for holding lengths of sheet material from movement away from the heat sealing station after positioning in the guide means.

5. Apparatus according to claim 4 wherein said holding means are a pair of air cylinders positioned on opposite 5 sides of the heat sealing station and a table surface is provided on opposite sides of the heat sealin station against which the sheet material is pressed by the cylinders.

6. Apparatus according to claim 1 including means for holding a ring element adjacent the heat sealing station in position for an end of sheet material to be inserted therethrough, and means for folding the inserted end portion of the sheet material around a portion of the ring and back against itself in overlapping relationship at the heat sealing station.

7. Apparatus according to claim 6 wherein said means for holding the ring includes a raised member mounted adjacent the heat sealing station about which the ring member fits, a first slide member reciprocally mounted to hold the ring against the shoulder portion with one portion of the ring spaced from the shoulder portion, a space great enough to permit the end portion of the sheet material to be inserted therebetween and a second slide member reciprocally slidable over the shoulder portion toward the heat sealing station to fold the inserted marginal end portion of the tape back against itself in overlapping relationship at the heat sealing station.

8. Apparatus according to claim 6 including switch means in position to be actuated by said guide means for automatically moving the heat sealing elements to and away from the heat sealing station as the guide means are moved away from and toward the heat sealing station.

9. Apparatus according to claim 6 wherein said guide means includes a first guide plate reciprocal to and away from the heat sealing station and inclined away from the ring holder, and a second sheet material edge abutting means positioned over the ring holder for holding the inserted marginal end portion of the sheet material in position to be folded over toward the heat sealing station.

References Cited UNITED STATES PATENTS DOUGLAS J. DRUMMOND, Primary Examiner.

U.S. Cl. X.R. 156-502, 583 

1. AAPPARATUS FOR OVERLAPPING PORTIONS OF SHEET MATERIAL AND HEAT SEALING THEM TOGETHER COMPRISING: (A) A PAIR OF HEAT SEALING ELEMENTS MOUNTED FOR RECIPROCAL MOVEMENT TO AND FROM A HEAT SEALING STATION, (B) MEANS FOR RECIPROCATING THE HEAT SEALING ELEMENTS TO AND FROM THE HEAT SEALING STATION, (C) SHEET MATERIAL GUIDE MEANS FOR RECEIVING PORTIONS OF SHEET MATERIAL AND POSITIONING THEM IN OVERLAPPING RELATIONSHIP AT THE HEAT SEALING STATION, AND (D) MEANS FOR MOVING THE GUIDE MEANS AWAY FROM THE HEAT SEALING STATION BEFORE MOVING THE HEAT SEALING ELEMENTS INTO CONTACT WITH THE SHEET MATERIAL AT THE HEAT SEALING STATION. 